Related Terms

The rating of the acid or alkalinity of a solution in a scale from 0 to 14.
It's based on the hydrogen ion concentration in a solution. Chemical solutions
with higher PH ratings are increasingly alkaline, while lower ones acid.
Distilled water is neutral with a PH rating of 7.

The "brown" in the name of this process gives you some
idea of the colour of the finished print -although tones tend to be delicate
rather than heavy - so clear, graphic images tend to work best.The process
involves combining iron salts with silver nitrate and either oxalic acid for a
warm-brown colour or tartaric acid for brown-black result. Tightly-woven fabrics
can be a better base than paper, as the finished "print" must be washed in
water. Exposure is by contact printing, but, because of the relatively high
sensitivity of the medium to light, you should work in dim conditions, and give
an exposure of around 1 minute in sunlight.Develop the image in a 1% borax
solution, fix it in traditional hypo, and give a final wash of at least 30
minutes.